The whole thing with the numbers is the octane, which in lamens terms means how hot it burns. The higher octane gases (in US 89 and 91) burn hotter which makes them more powerful. Engines are designed with a certain fuel usage in mind.

AS far as that design goes: Compression Ratio. Thats why higher end cars get knock whne using low octane gas. It does get the reuired power from the burned fuel.

The terms regualar and premium or whatever is on the pump is a misleading.. Its a sales pitch. MOST people drive an aisian import or mid class american car that takes 87... but to get these people to pay more for gas they call 91 "premium" and people think its better for their cars... not true.

BTW, I use chevron and shell... chevron with techron, and shell has nitrogen enriched fuel... I dont ever use fuel additives...

The whole thing with the numbers is the octane, which in lamens terms means how hot it burns. The higher octane gases (in US 89 and 91) burn hotter which makes them more powerful. Engines are designed with a certain fuel usage in mind.

AS far as that design goes: Compression Ratio. Thats why higher end cars get knock whne using low octane gas. It does get the reuired power from the burned fuel.

The terms regualar and premium or whatever is on the pump is a misleading.. Its a sales pitch. MOST people drive an aisian import or mid class american car that takes 87... but to get these people to pay more for gas they call 91 "premium" and people think its better for their cars... not true.

BTW, I use chevron and shell... chevron with techron, and shell has nitrogen enriched fuel... I dont ever use fuel additives...

7Rage

01-18-2013 10:08 AM

I only use 91 here in america... but all grades have the techron, it's their signature selling point

rdorman

01-18-2013 10:12 AM

Top tier premium. Here shell is most available.

rdorman

01-18-2013 10:13 AM

Quote:

Originally Posted by Piers1989
(Post 7321690)

Here in the UK our "worst" fuel is 95, then we have a choice between 97 and 99 depending on where you go for super.

95 RON is like 89-90 here.

ve39

01-18-2013 10:15 AM

hrm so i guess everyone is staying away from 87, even though manual suggests it won't break the car.
I only use Chevron and put 87 in all my cars and never had any problems. when i do put 91 i see my consumption get worse for some reason when it should be better.

7Rage

01-18-2013 10:18 AM

who says consumption should get better.... their is no difference in "quality" of different grades of fuel from the same station.... that is what they want you to think... but worse? maybe your injectors should be cleaned....?

The whole thing with the numbers is the octane, which in lamens terms means how hot it burns. The higher octane gases (in US 89 and 91) burn hotter which makes them more powerful. Engines are designed with a certain fuel usage in mind.

AS far as that design goes: Compression Ratio. Thats why higher end cars get knock whne using low octane gas. It does get the reuired power from the burned fuel.

The terms regualar and premium or whatever is on the pump is a misleading.. Its a sales pitch. MOST people drive an aisian import or mid class american car that takes 87... but to get these people to pay more for gas they call 91 "premium" and people think its better for their cars... not true.

BTW, I use chevron and shell... chevron with techron, and shell has nitrogen enriched fuel... I dont ever use fuel additives...

Octane has zero to do with heat, btu output. Higher burns slower which leads to knock resistance. Static compression ratio is only one factor, has nothing to do with the price of the car and again, energy content is the same. In so far as octane is concerned, if it takes 87 then running higher is of no benefit. However, the premium tends to be blended with a better additive package.

Both shell and chevron are 'good' gas so you have that going for you!

rdorman

01-18-2013 10:24 AM

Quote:

Originally Posted by ve39
(Post 7322205)

hrm so i guess everyone is staying away from 87, even though manual suggests it won't break the car.
I only use Chevron and put 87 in all my cars and never had any problems. when i do put 91 i see my consumption get worse for some reason when it should be better.

There is a minimum and a recommended. Minimum will not 'break' your car but for it to perform at optimum parameters then you need recommended. As for worse when you switch, most likely perception and use by the one behind the wheel.

7Rage

01-18-2013 10:28 AM

Quote:

Originally Posted by rdorman
(Post 7322213)

has nothing to do with the price of the car

not what I said... i said higher end cars tend to take only premium fuels because they have performance specs that utilize that octane to run at peak performance, where as you will never see a civic read "use premium fuel only".. They take 87 becasue thats what grade fuel they were designed to use...

Quote:

Originally Posted by rdorman
(Post 7322213)

In so far as octane is concerned, if it takes 87 then running higher is of no benefit.

THis is true, I thought that I had implied this but re-reading it it seems to have been omitted.

Quote:

Originally Posted by rdorman
(Post 7322213)

However, the premium tends to be blended with a better additive package.

additives have nothing to do with it... different oil companies use different additives... they're marketing ploys good man... the car says "use premium fuel only" not "use chevron because it has techron, and that makes your BMW run the best"

7Rage

01-18-2013 10:32 AM

Octane rating or octane number is a standard measure of the performance of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating. In broad terms, fuels with a higher octane rating are used in high-compression engines that generally have higher performance. In contrast, fuels with low octane numbers (but high cetane numbers) are ideal for diesel engines. Use of gasoline with less octane numbers may lead to the problem of engine knocking. - Straight from wikipedia.... what I said in earlier posts was from my knowledge... wikipedia just backed it up

tho the heat thing was off, but only a little.... it can burns at higher compreesion and not heat....

and I am aware you said compression was only one factor, but is the biggest

Plain and simple Bruh

" price has nothing to do with the car ":tsk:

generally is the keyword

rdorman

01-18-2013 11:02 AM

Quote:

Originally Posted by 7Rage
(Post 7322239)

not what I said... i said higher end cars tend to take only premium fuels because they have performance specs that utilize that octane to run at peak performance, where as you will never see a civic read "use premium fuel only".. They take 87 becasue thats what grade fuel they were designed to use...

THis is true, I thought that I had implied this but re-reading it it seems to have been omitted.

additives have nothing to do with it... different oil companies use different additives... they're marketing ploys good man... the car says "use premium fuel only" not "use chevron because it has techron, and that makes your BMW run the best"

Just a little friendly poking.... Chevy volt recommends premium. How about the smartcar? Premium. Mini cooper? Not what I would call higher end! Which was kind of the point. Higher end generally = higher price. As for additives. The base fuel is blended as it is mixed into the delivery tanker. Not marketing.... At least not completely! Premium normally receives a higher additive package. And BMW recommends top-tier fuel which includes chevron... And generally premium ( no direct correlation between the two of course).

And just or fun, some civics read 'use premium only' :)

ve39

01-18-2013 11:12 AM

high end or not high end our 7s do not read premium fuel only. this is my 3rd 7 series and 5th bmw and i used 87 on all of them without a problem. I'm not cheaping out but i just hate wasting when there is no need.
really wanted to see what you guys used for fuel but i guess i'm the only one using 87 so far...

7Rage

01-18-2013 11:20 AM

smart and mini are bmw companies which I am sure you know.... not "high perfromance" but "high end" yes lol.... I thought volt was all electric not hybrid? unless they have a hybrid model.... at work tho, cant check...

and hte civis using premium? wth? i guess with newer tech being so cheap..... i.e. VVT being on all cars now.. my xterra uses 89... so yeah, i guess.. but then again its a 35k car and not 15-25k, like kia's or versa.. but 12 years ago mbz and bmw needed premium where the hondas didnt :)...

"friendly poking" :)

check on new mustang "build your own" see diffences in GT or BOSS ..lmao 20hp gain when using 91 over 87...

7Rage

01-18-2013 11:22 AM

Quote:

Originally Posted by ve39
(Post 7322340)

high end or not high end our 7s do not read premium fuel only. this is my 3rd 7 series and 5th bmw and i used 87 on all of them without a problem. I'm not cheaping out but i just hate wasting when there is no need.
really wanted to see what you guys used for fuel but i guess i'm the only one using 87 so far...

high end or not high end our 7s do not read premium fuel only. this is my 3rd 7 series and 5th bmw and i used 87 on all of them without a problem. I'm not cheaping out but i just hate wasting when there is no need.
really wanted to see what you guys used for fuel but i guess i'm the only one using 87 so far...

Then you have your answer.

ve39

01-18-2013 11:25 AM

maybe US and CAD cars have different stickers and manuals. why would they say "premium unleaded fuel 91 only" and in the manual saying that 87 could be used too without harm